Subtract 9/12 from 45/90, Solve 45/90

Subtract 9/12 from 45/90

45/90 - 9/12 is -1/4.

Find the least common denominator or LCM of the two denominators:
LCM of 90 and 12 is 180

Next, find the equivalent fraction of both fractional numbers with denominator 180
For the 1st fraction, since 90 × 2 = 180,
45/90 = 45 × 2/90 × 2 = 90/180
Likewise, for the 2nd fraction, since 12 × 15 = 180,
9/12 = 9 × 15/12 × 15 = 135/180
Subtract the two like fractions:
90/180 - 135/180 = 90 - 135/180 = -45/180
After reducing the fraction, the answer is -1/4

MathStep (Works offline)

Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad